Environmental Engineering Reference
In-Depth Information
Table 7.1 Physical properties of four nitroalkanes [
1
]
Properties
CH
3
NO
2
C
2
H
5
NO
2
CH
3
CH
2
CHNO
2
(CH
3
)
2
CHNO
2
Mt
61.04
75.07
89.09
89.09
ʸ
b
/
°
C
101.2
114.0
131.6
120.3
ʸ
a
/
°
C
28.55
90
108.0
93.0
−
−
−
−
ρ
/g cm
−
3
1.139
1.052
1.033
0.992
C)/N.m
−
1
˃
(20
°
3.78
3.19
3.06
3.06
ʸ
f
/
°
C
44.4
41.1
48.9
39.5
ʸ
D
/
°
C
420.0
414.4
420.6
427.8
Low explosive limit of
mixture in air
×
100
7.3
4.0
2.6
2.6
Apparently, it appears that the detonation velocity decreases with the increase of
temperature, which mainly should be due to the reduced density.
Because the detonation velocity of nitromethane is highly dependent on tem-
perature, experimental conditions (tube constraining strength, detonation capability,
etc.), experimental errors and others, results reported in the literature appeared to be
substantially different. Table
7.2
showed the detonation velocity of nitromethane
reported by Urbanski et al. [
32
]. In addition, it was found that the detonation
pressure of nitromethane is 13 GPa, detonation reaction time is (22
10
−
9
s,
explosion heat is 5141.4 kJ kg
−
1
, and explosion product volume is 936 L kg
−
1
.As
nitromethane is not easy to detonate, strong boosters were often used under dra-
matically different experimental conditions, therefore, its power data documented in
the literature are largely discrepant. At this stage, the lead block expansion value of
nitromethane has been determined to be about 400 mL. Based on these results, one
can conclude that nitromethane is a high explosive with strong power, and its
detonation velocity is approximately equal to the one of RDX with the same
density.
±
3)
×
(a)
(b)
50
40
6.4
30
20
6.3
10
0
6.2
-10
-20
6.1
-30
-20
-10
0
10
20
30
40
50
60
70
-30
-20
-10
0
10
20
30
40
t/ ˚C
t/ ˚C
Fig. 7.1 Effect of temperature on critical diameter and detonation velocity of nitromethane [
1
],
a detonation velocity (brass tube
